a(n) is the smallest natural number m such that m = pi(n*m). For all known terms of this sequence the relation, " 2.4*a(n) < a(n+1) < 2.7*a(n) + 7 " is true. A038627(n) gives number of natural solutions of the equation m = pi(n*m). - Farideh Firoozbakht, Jan 09 2005

REFERENCES

S. W. Golomb, On the Ratio of N to pi(N), American Mathematical Monthly, 69 (1962), 36-37.